Backup is the pet of Veronica Mars (Kristin Bell), a slender,
petite, blonde 17-year-old who attends Neptune High School in
Southern California.

Veronica's father Keith Mars (Enrico Colantoni) is a
full-time detective and his daughter helps run his office and
occasionally investigates cases on her own. When Veronica leaves the
house, her father often reminds her to "take her Backup."

Backup's personal traits were revealed during a phone conversation
between Veronica and her father, when she said to Keith that she
would be safe at home "with the only sane member of the Mars
family." To which Keith replied "The one who eats from the garbage
and keeps bringing me dead birds?"

Although formidable looking, Backup is a pleasant pooch who
willingly does the bidding of his mistress. Well almost. Once when

Veronica's ex-boyfriend, Duncan Kane (Teddy Dunn) approached her
while she was walking the dog, she told him to stay back or she
would sick Backup on him. But ol' Backup sensed no danger from
Duncan and happily wagged his tail and tongue, much to Veronica's
chagrin.

However, if Backup did sense danger he was on top of things
immediately, like the time Veronica was on stakeout in her LeBaron
at the Camelot Motel and Weevil (Francis Capra) and his biker
friends tried to threaten her. As one of the bikers reached through
the window, Backup charged the assailant and bite at his arm, while
Veronica dispatched another with her trusty little taser gun.

Backup later helped nab Aaron Echolls (Harry Hamlin), the killer of
Lilly Kane (Veronica's best friend) when he tried to steal Keith
Mars car. What Echolles didn't know was that Backup was inside the
car. Startled and foiled by the snarling canine, Echolls stumbled
into the nearby highway and was hit by a flower delivery van.

Veronica and Backup (1)

TRIVIA NOTE: There have been two Backups on the show. The
original Backup (referred
to as 1.0 and seen in the pilot and early episodes) was a white and
brown 2.5 year American bulldog named Gordo trained by Omar von
Muller of All Stars Kennel.

Unfortunately, the first Backup was replaced when he didn't live up
to the expectation of the show's creator, Rob Thomas. Here is an excerpt from an interview
which explains the reason the dog was replaced:

RT: I couldn't deal with his trainer. I loved the original Backup --
he was such a beautiful dog. But his trainer had a month and a half
to get him ready for the scene in the pilot, and he didn't do it. He
needed to fly out of the car, and he just couldn't -- he sort of
slid down the window. So a stuntman had to pull him out on his arm.
Then, to make it look good, he was supposed to attack the biker, who
was wearing protective padding, but he wouldn't do that either. We
had to cut together all this footage and loop in growling. It was
just a mess, and the trainer blamed us! So rather than strangle the
guy, I recast Backup.

The replacement Backup was called Lefty. He made his first
appearance in episode No. 4 "The Wrath of Con" as Veronica, her
father, Keith Mars and Backup the dog visit the campus of San Diego
State while on a case. Lefty's movie credits include the film Alpha
Dog (2006) as Adolph, Johnny Truelove's dog.

There is also a Backup 1.5. This is the name given to the stuffed
brown toy dog found in Veronica Mars' bedroom.